In the wake of a tanker accident in January, the Bay Bridge was added to a list of nine other areas that will restrict bar pilots from sailing their large commercial vessels in heavy fog.

The addition of the Bay Bridge, along with some other temporary guidelines, came after a vote on Thursday of the Harbor Safety Committee of San Francisco Bay. Still, they take effect immediately and will be reviewed again in the coming year, according to Coast Guard Chief Petty Officer Michael Lutz.

Raw Video: Tanker Nicks Bay Bridge

Under the new guidelines, all large ships weighing more than 1,600 tons will be prevented from sailing under the bridge - while on an outbound route - when visibility is less than half a mile. The inbound traffic is not bound to such guidelines.

The Bay Area's other bridges are already on this list of "Critical Maneuvering Areas."

The vote comes after a tanker, named the Overseas Reymar, nicked the base of the Bay Bridge on Jan. 7, raising alarm about how the accident could have occur ed.

These rules, albeit temporary, will be implemented immediately by the Coast Guard, according to Deb Self, a committee member and the executive director at Baykeeper. Her group also championed the stricter guidelines.

On the day in question, there was indeed foggy, though unclear just how foggy. The bar pilot, Guy Kleess had been in contact with the the Coast Guard's Vessel Traffic Service personnel that morning, according to U.S. Coast Chief Petty Officer Mike Lutz. But the exact conversation is still under investigation and has not yet been made public.

Now that the Bay Bridge is on the official list, Coast Guard crews will recommend that the large vessels not travel when visibility is less than a half mile.

The other guidelines include that captains and pilots of large ships:

• Vessels operators should make visibility reports as part of their sailing plan report to the Vessel Traffic Service and at any point in their transit when visibility conditions change substantially.
• Vessels transiting the San Francisco - Oakland Bay Bridge, west of Yerba Buena Island, in any condition of reduced visibility should generally do so through the A-B or D-E span unless vessel traffic, environmental or other safety factors dictate otherwise. Outbound vessels should not make this transit when visibility is less than 0.5 nautical miles.
• Outbound or northbound vessels should not transit the San Francisco - Oakland Bay Bridge, west of Yerba Buena Island, when visibility is less than 0.5 nautical miles.
• Inbound vessels transiting the San Francisco - Oakland Bay Bridge in restricted visibility are advised to exercise caution during their transit.

These guidelines are in addition to the nine CMAs and associated restrictions on operating in reduced visibility already in place throughout the San Francisco Bay.

IF YOU ARE INTERESTED: Here is the full list of the critical maneuvering areas identified by the San Francisco Harbor Safety Committee. Following these guidelines are considered "best practices" for the maritime industry.